Redmond O' Neal's father Ryan has visited him in rehab, against his doctor's advice

The 26 year old – whose mother is Farrah Fawcett - was recently ordered to undergo a one year treatment programme at a court ordered rehab facility after being arrested on heroin and firearms charges and while his doctor advised against contact with his father, Ryan was adamant he wanted to see his son.

A source said: "Ryan was allowed to visit, against Redmond’s doctor’s orders, as it was thought the visit would be beneficial to Redmond."

Although Redmond - who was jailed initially following his arrest because the offence marked a breach of probation set following a prior heroin possession conviction - narrowly escaped a prison sentence, friends admitted they are worried being sentenced to the rehab in West Lost Angeles is not enough.

The source added: "Rehab might not be the best fit for Redmond. Rehab is not jail, and there are concerns about the lack of security where he is now. It's not regimented and is run much more loosely than a prison would be. Redmond needs a very strict and secure environment, the last thing he needs is someone sneaking drugs into him … Redmond doesn't grasp that his addiction to heroin could kill him."